21985

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has period 81.at n=22A020420
• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 32.at n=3A031620
• Number of partitions in parts not of the form 17k, 17k+3 or 17k-3. Also number of partitions with at most 2 parts of size 1 and differences between parts at distance 7 are greater than 1.at n=42A035964
• Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-1111-0001 pattern in any orientation.at n=16A146851
• n^3 + n-th cubefree number.at n=27A180499
• Number of 0..6 arrays of length n with each element differing from at least one neighbor by 1 or less, starting with 0.at n=7A221681
• Expansion of Product_{k>=2} (1 + k*x^k).at n=23A317913
• Number of compositions of n such that one maximal run is the longest.at n=16A391595